The present invention relates to a solenoid valve.
Such a solenoid valve is referred to, for example, in European Published Patent Application No. 0 690 223, in which the solenoid valve is used to control an electrically controlled fuel injector.
Such a solenoid valve is also referred to, for example, in German Published Patent Application No. 196 50 865, in which the solenoid valve has an armature having a multi-part construction. To avoid post-pulse oscillation of an armature plate after the solenoid valve has closed, a damping device is provided on the armature.
In solenoid valves, a magnet assembly, for example, maybe screwed to an injector body or fuel injector housing using a magnet lock nut. The relatively complex and costly mounting required for this screw connection may be disadvantageous. In addition, magnet lock nuts may loosen during operation of the solenoid valve, which may impair the reliability and effectiveness of the solenoid valve. Magnet lock nuts should be manufactured from a relatively hard material, such as steel alloys, for example, ETG 100.
An object of the present invention is to provide an improved option for connecting the magnet assembly and injector body of a solenoid valve.
Using an exemplary approach according to the present invention, it is believed that an injector body may be mounted on a magnet assembly more simply and less costly, compared with conventional approaches. An installation tool, which is required for this operation, may be easier and more economical to provide, compared to open-end wrenches (controlled via a screw station having a force transducer) customarily used for tightening magnet lock nuts. During installation according to the present invention, the connecting element is uniformly deformed, whereas with tightened magnet lock nuts, an oval or non-uniform deformation has been observed. To achieve the connection according to the present invention, bolts may be used which, in a uniform manner or in segments of equal size, exert pressure circumferentially on the retaining ring used as the connecting element. The described connection according to the present invention may allow the cycle time to be reduced during the manufacture of solenoid valves, so that exemplary solenoid valves according to the present invention may, for example, be suitable for mass production.
The retaining ring may, for example, include two crimped edges that cooperate with the corresponding grooves and/or projections of the injector body or magnet assembly, respectively. The two crimped edges help assure a firm connection between the magnet assembly and the injector body, in a robust and reliable manner.
According to one exemplary solenoid valve of the present invention, the retaining ring is more elastic than the magnet lock nuts. The required elasticity is determined by particular circumstances, and the connecting ring may include, for example, stainless steel alloys, such as 1.4303 or 1.4301 alloys.
The retaining ring may include a lateral recess. Such a recess may, for example, be used as a rupture point or break point, so that the retaining ring may be easily detached, to loosen the connection between the magnet assembly and the injector body. This helps ensure that no contaminations appear when the solenoid valve is disassembled. For example, the formation of particles or shavings, which may appear when loosening conventional magnet lock nuts, may be prevented.